“Big Bang Theory” star and UCLA alumnus Mayim Bialik said in May that she wouldn’t speak at the UCLA College graduation as scheduled due to a labor dispute between the university and service workers. “These issues are near and dear to my heart, especially since the LAUSD teachers’ union helped support my family for my entire young life,” the actress said in a statement released by the university. (File photo by Matt Winkelmeyer/Getty Images)

LOS ANGELES — UCLA Chancellor Gene Block will be filling in Friday as the keynote speaker during UCLA College commencement ceremonies, replacing actress Mayim Bialik, who withdrew amid a labor dispute between the university and service workers.

Block will speak in place of Bialik, a UCLA grad best known for her role as neurobiologist Amy Farrah Fowler on CBS’ “The Big Bang Theory.” Bialik received a bachelor of science degree in neuroscience with a minor in Hebrew and Jewish studies from UCLA in 2000 and a doctorate in neuroscience from UCLA in 2007.

Although she had been announced previously as the UCLA College commencement speaker, she withdrew in late May, responding to a call from the union representing University of California service workers amid a labor dispute.

“These issues are near and dear to my heart, especially since the LAUSD teachers’ union helped support my family for my entire young life,” Bialik said in a statement released by the university. “I send deepest regrets to the UCLA community and I hope to be able to join you soon to celebrate your accomplishments.”

Block will speak in Bialik’s place at both the 2 and 7 p.m. commencement ceremonies at Pauley Pavilion.